JP2003222927A - Shutter device for camera - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain the bound phenomenon of a shutter blade caused in the case of closing operation. <P>SOLUTION: The shutter device is equipped with the shutter blades 31 and 32 supported to freely turn around supporting shafts 11 and 12 on a bottom board 10 and opening/closing an aperture part 10a, an electromagnetic actuator 40 driving the blades 31 and 32, and stoppers 13, 14, 15 and 16 on which the blades 31 and 32 actuated by the actuator 40 are made to abut and are stopped. Inclined surfaces 13a and 14a inclined by an angle θ to a line L passing the supporting shafts 11 and 12 are formed on at least the closing stoppers 13 and 14, and the blades 31 and 32 are made to abut on the surfaces 13a and 14a and stopped. Thus, reaction force R by impact force F obtained when the shutter blade is rotated and moved and abuts on the stopper becomes weak and the bound phenomenon of the shutter blade is restrained or prevented. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a camera shutter device for driving a shutter blade for opening and closing an exposure opening by an electromagnetic drive source, and more particularly to a camera shutter device applied to a digital camera.

[0002]

2. Description of the Related Art A conventional shutter device for a camera mounted on a digital camera or the like drives a shutter blade and a shutter blade rotatably provided on a main plate so as to open and close an exposure opening. There is known an electromagnetic actuator having a drive pin, a closing stopper that stops the shutter blade after the closing operation, an opening stopper that stops the shutter blade after the opening operation, and the like. In this device, the shutter blade is positioned in contact with the opening stopper by the magnetic biasing force of the electromagnetic actuator at the standby position where the opening is opened, while it is closed during the closing operation for closing the opening. It can be stopped by contacting the stopper.

[0003]

By the way, in the above-mentioned conventional apparatus, as shown in FIG. 10, for example, the closing stopper 2 for stopping the shutter blade 1 at the closed position has the contact surface 2a thereof on the shutter blade 1. Was formed so as to be located on a straight line L (parallel to the straight line L) passing through (the substantial center of) the support shaft 3 of. Therefore, when the electromagnetic actuator 4 is actuated to move the shutter blade 1 at a high speed from the standby position shown by the chain double-dashed line toward the closed position shown by the solid line and abut against the closing stopper 2, the shutter blade 1 rotates. The impact force F due to the movement acts vertically on the contact surface 2a of the stopper 2.

As a result, the reaction force R from the stopper 2
Is equivalent to the impact force F and becomes the opposite force −F, and the impact force F
Becomes larger, the reaction force R also becomes larger, causing the shutter blade 1 to bounce. Such a bouncing phenomenon causes re-exposure, re-closing, etc., which is not preferable. On the other hand, when the traveling speed is low, the bounce phenomenon is suppressed, but the exposure time becomes long.

The present invention has been made in view of the above points, and it is an object of the present invention to suppress or prevent the bounce phenomenon of shutter blades while simplifying the structure and reducing the cost. SUMMARY OF THE INVENTION It is an object of the present invention to provide a camera shutter device that can obtain a stable exposure operation without variations.

[0006]

A camera shutter device of the present invention comprises a substrate having an opening for exposure, and shutter blades which are rotatably supported around a support shaft on the substrate to open and close the opening. A shutter device for a camera, comprising: an electromagnetic drive source for driving the shutter blades; and a stopper for bringing the shutter blades operated by the electromagnetic drive source into contact with the shutter blades to stop the shutter blades. In order to make it have an inclined surface inclined to a straight line passing through the support shaft,
It is characterized by that. According to this configuration, the impact force when the shutter blade travels (rotates) and contacts the stopper is dispersed in the direction along the inclined surface and in the normal direction, and the reaction force in the normal direction causes the shutter blade to move. It will act as a pushing back force. That is, since this reaction force is smaller than the impact force, the bound phenomenon of the shutter blades can be suppressed or prevented as compared with the case where the impact force becomes the reaction force as it is.

In the above structure, it is possible to adopt a structure in which the stopper is a closing stopper that stops the shutter blade after the closing operation of the opening. According to this configuration, when the exposure time is defined by the closing operation of the shutter blades, for example, when applied as a shutter device of a digital camera, by suppressing or preventing the bounce phenomenon, a good exposure operation is obtained. be able to.

In the above structure, it is possible to adopt a structure in which the inclined surface is formed so as to face the outside not facing the support shaft. According to this structure, since the inclined surface is formed so as to face outward rather than face the support shaft side, when the shutter blade collides with the inclined surface of the stopper, the shutter blade is separated from the support shaft and the inclined surface. It is possible to prevent it from biting in between and being locked, and it is possible to effectively suppress or prevent the bounce phenomenon.

In the above structure, there is provided control means for controlling energization to the electromagnetic drive source, and the control means is arranged in a direction opposite to the direction in which the shutter blade is moved relative to the electromagnetic drive source immediately before the shutter blade is moved. It is possible to adopt a configuration that energizes in the direction. According to this configuration, when the electromagnetic drive source is driven to move the shutter blades, by energizing in the opposite direction, the rise delay of the capacitor used in the normal feedback type constant current drive circuit can be eliminated, The travel of the shutter blades can be performed with higher accuracy.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. 1 to 5
FIG. 1 shows an embodiment of a camera shutter device according to the present invention. As shown in the figure, this camera shutter device includes a base plate 10 as a substrate having exposure openings 10a and 20a, a holding plate 20, and openings 10a and 20a.
A shutter blade 30 for opening and closing the shutter blade, an electromagnetic actuator 40 as an electromagnetic drive source for driving the shutter blade 30, a control circuit (not shown) including a CPU as a control unit for controlling energization of the electromagnetic actuator 40, and the like. .

The electromagnetic actuator 40 is shown in FIGS.
As shown in FIG. 3, the rotor 41 is magnetized to the N pole and the S pole and is rotatably supported in a predetermined angle range, the exciting coil 42, the cylindrical yoke 43 forming a magnetic circuit, and the like. ing. The rotor 41 is integrally formed with a drive pin 41a connected to the shutter blade 30 at a position deviated from the center of rotation.

As shown in FIGS. 1, 3 and 4, the main plate 10 has an opening 10a for exposure, support shafts 11 and 12 for supporting the shutter blades 30, and a closing operation to reach a closed position. Close stopper 1 for stopping shutter blade 30
3 and 14, opening stoppers 15 and 16 that stop the shutter blade 30 that has reached the standby position by performing the opening operation are formed. Further, as shown in FIG. 2, a blade chamber W for rotatably housing the shutter blades 30 is formed between the base plate 10 and the pressing plate 20.

The shutter blade 30, as shown in FIGS. 3 and 4, has a first shutter blade 31 and a second shutter blade 3.
It is composed of two. The first shutter blade 31 and the second shutter blade 32 have circular holes 31a and 32a, respectively.
And elongated holes 31b and 32b are formed. Then, the support shafts 11 and 12 of the main plate 10 are inserted into the circular holes 31a and 32a, and the first shutter blade 31 and the second shutter blade 32 are inserted.
Are rotatably supported. Also, the long holes 31b, 3
The drive pin 41a is inserted into 2b.

Therefore, the rotation of the rotor 41 causes the first shutter blade 31 and the second shutter blade 32 to rotate.
Are close to each other, for example, from the standby position (the position where the opening 10a is opened) shown in FIG. 3 to the closed position (the position where the opening 10a is closed) shown in FIG. 4 and to return to the standby position again. And the opening 10a is rotated so as to be separated.
It is designed to open and close.

Here, as to the closing stoppers 13 and 14, as shown in FIG. 4, the first shutter blade 31 and the second shutter blade 31 are provided.
The portions of the shutter blade 32 where the leading edge portions 13c, 14c contact each other are inclined surfaces 13a, 1 inclined by a predetermined angle θ with respect to the respective straight lines L passing through substantially the centers of the support shafts 11, 12.
4a. Also, these inclined surfaces 13
The a and 14a are formed so as to incline toward the outside that does not face the support shafts 11 and 12, respectively.

That is, as shown in FIG. 5, regarding the first shutter blade 31, a straight line L connecting the substantial center of the support shaft 11 and the substantially central portion of the inclined surface 13a of the closing stopper 13 and an extension line of the inclined surface 13a. S and S are formed to form an angle θ. The operation of the inclined surface 13a will be described below.
The impact force F generated when the shutter blade 31 travels (rotates counterclockwise) and its tip edge portion 31c contacts the closing stopper 13 is dispersed in the direction along the inclined surface 13a and the normal direction. The reaction force R in the normal direction acts as a force to push back the first shutter blade 31. That is, the reaction force R becomes smaller than the impact force F (R
= −FCOS θ, R <│−F│), and the bounce phenomenon of the first shutter blade 31 is suppressed or prevented as compared with the case where the impact force F becomes a reaction force as it is. The second shutter blade 32 (tip edge portion 32c) and the closing stopper 14
The relationship between (the inclined surface 14a) is the same as the relationship between the first shutter blade 31 and the closing stopper 13 described above.

Further, the inclined surfaces 13a and 14a are attached to the support shaft 11,
Since the first shutter blade 31 and the second shutter blade 32 are formed so as not to face the 12 side but to the outer side which is the opposite side, the inclined surfaces 13 of the stoppers 13 and 14 are closed.
When colliding with a and 14a, the first shutter blade 31 bites between the support shaft 11 and the inclined surface 13a, and the second shutter blade 32 bites between the support shaft 12 and the inclined surface 14a. You can prevent it from being locked.

Here, the angle .theta. Is preferably a larger angle in order to disperse the impact force F as much as possible and reduce the reaction force R in the normal direction. On the other hand, if it is too large, the inclined surface 13a and the first shutter are not necessary. The frictional force due to the contact between the contact surface of the blade 31 (the tip edge portion 31c) and the inclined surface 14a and the contact surface of the second shutter blade 32 (the tip edge portion 32c) increases, and the return operation is performed in the opposite direction. In this case, the load increases, so the angle is set to an appropriate angle considering both factors. Here, the angle θ is preferably set in the range of approximately 10 ° to 45 °, but is not limited to this range.

Next, the operation of this camera shutter device when mounted on a digital camera will be described with reference to the time chart shown in FIG. The control circuit as the control means for controlling the drive of the electromagnetic actuator 40 has a CP that performs various arithmetic processes and issues a control signal.
U, a feedback type constant current drive circuit, a capacitor for stopping oscillation of this drive circuit, and the like.

First, when the main switch of the camera is turned on and the camera is in a standby state waiting for photographing, the electromagnetic actuator 40
A magnetic biasing force that rotates to the open side in the non-energized state is applied to the rotor 41 of FIG. And is held at the standby position where the opening 10a is opened.

When the photographer performs a release operation in this standby state, the control circuit is activated immediately before the first shutter blade 31 and the second shutter blade 32 are closed, as indicated by the area A in FIG. First, the electromagnetic actuator 40 is energized in the direction (opening direction) opposite to the direction in which it travels closed (closing direction), and then in the closing direction as indicated by region B.

As a result, the rise delay of the oscillation stopping capacitor in the feedback constant current drive circuit is eliminated, and the first
The shutter blades 31 and the second shutter blades 32 start traveling with high accuracy (at a predetermined timing and a predetermined speed). Here, when the first shutter blade 31 and the second shutter blade 32 are not reliably positioned by the opening stoppers 15 and 16, the traveling start position is also positioned.

Due to the energization in the closing direction (area B), the first shutter blade 31 and the second shutter blade 32 rotate at high speeds respectively, and as shown in FIG.
When reaching the position where 0a is closed (closed position), the respective tip edge portions 31c and 32c come into contact with the inclined surfaces 13a and 14a of the closing stoppers 13 and 14 and stop. At this time, as described above, the reaction force R of the impact force F exerted on the closing stoppers 13 and 14 by the first shutter blade 31 and the second shutter blade 32 becomes a component in the normal direction of the inclined surfaces 13a and 14a. Since it is smaller than the impact force F, the bounce phenomenon of the first shutter blade 31 and the second shutter blade 32 is suppressed or prevented. As a result, the exposure operation is stably and highly accurately performed.

After that, as shown in the area C in FIG. 6, the coil 42 is de-energized, the rotor 41 is held in that position by the magnetic biasing force, and the first shutter blade 31 and the second shutter blade 31
The shutter blade 32 is also held in the closed position. An exposure operation is performed by closing and moving the shutter blades 30, and then a captured image captured by the CCD is captured by the image storage processing circuit, various processing is performed, and one image capturing is completed.

Thereafter, when the control circuit energizes the coil 42 of the electromagnetic actuator 40 in the opposite direction, as indicated by the area D in FIG. 6, the first shutter blade 3
The first and second shutter blades 32 run open, reach the standby position shown in FIG. 3, abut on the open stoppers 15 and 16, and stop. After that, the coil 42 is de-energized, and the magnetic urging force of the rotor 41 holds the first shutter blade 31 and the second shutter blade 32 at the standby position and waits for shooting. In the subsequent shooting, the above sequence is repeated.

7 to 9 show another embodiment of the camera shutter device according to the present invention. The same components as those in the above-described embodiment are designated by the same reference numerals and the description thereof will be omitted. In this device, as shown in the drawing, the shutter blades 300 (the first shutter blades 310
Also, the root side edge portions 310c and 320c located near the support shafts 11 and 12 of the second shutter blade 320) are brought into contact with the closing stoppers 130 and 140 and stopped.

That is, the main plate 10 'has a structure shown in FIGS.
As shown in FIG. 1, the spindle 1 that supports the shutter blades 300
Close stoppers 130 and 140 are formed in the vicinity of 1 and 12 to stop the shutter blade 300 that has reached the closed position by performing the closing operation.

As shown in FIGS. 7 and 8, the shutter blade 300 is composed of a first shutter blade 310 and a second shutter blade 320, and the first shutter blade 310 and the second shutter blade 320 have circular holes, respectively. 310a,
320a, the elongated holes 310b and 320b, and the root side edge portions 130c and 14 that abut the closing stoppers 130 and 140.
0c is formed.

Here, as to the closing stoppers 130 and 140, as shown in FIG. 8, the root side edge portions 130c and 14 of the first shutter blade 310 and the second shutter blade 320 are formed.
The portions where 0c abuts are formed as inclined surfaces 130a and 140a that are inclined by a predetermined angle θ with respect to the respective straight lines L passing through the substantial centers of the support shafts 11 and 12. Also,
These inclined surfaces 130a and 140a are respectively attached to the support shaft 1
It is formed so as to incline toward the outside that does not face 1 and 12.

That is, as shown in FIG. 9, regarding the first shutter blade 310, a straight line L connecting the substantial center of the support shaft 11 and the substantially central portion of the inclined surface 130a of the closing stopper 130 and an extension line of the inclined surface 130a. S and S are formed to form an angle θ. The operation of the inclined surface 130a will be described. The impact force F ′ when the first shutter blade 310 travels (rotates counterclockwise) and its root side edge portion 310c abuts on the closing stopper 130 is the inclination. The reaction force R ′ distributed in the direction along the surface 130 a and in the normal direction acts as a force to push back the first shutter blade 310.

That is, the reaction force R ′ is smaller than the impact force F ′ (R = −F′COSθ, R ′ <│−
F ′ |), the bounce phenomenon of the first shutter blades 310 is suppressed or prevented as compared with the case where the impact force F ′ directly becomes a reaction force. The second shutter blade 320 (root side edge portion 320c) and the closing stopper 140 (inclined surface 1)
40a), the first shutter blade 31
The relationship between 0 and the closing stopper 130 is similar.

In this embodiment, in particular, the support shaft 1
The length of the arm from 1, 12 to the root side edge portions 130c, 140c is the tip edge portions 13c, 14 in the above-described embodiment.
It is shorter than the arm length up to c. Therefore, the shutter blades 300 rotate to close the stopper 1
When colliding with 30, 140, the collision will occur at a slower speed than in the above-described embodiment.

Further, similarly to the above-described embodiment, the inclined surface 13
0a and 140a are formed so as not to face the support shafts 11 and 12 but to the outer side which is the opposite side.
When the shutter blades 310 and the second shutter blades 320 collide with the inclined surfaces 130a, 140a of the closing stoppers 130, 140, the first shutter blades 310 are provided between the support shaft 11 and the inclined surface 130a, and the second shutters. It is possible to prevent the blades 320 from being bitten and locked between the support shaft 12 and the inclined surface 140a.

Here, the angle θ is preferably set in the range of about 10 ° to 45 ° in consideration of the reaction force R ′, the frictional force with the inclined surfaces 130a and 140a, and the like, as in the above embodiment. To be done.

In the above embodiment, the shutter blade 3
0,300, a pair of shutter blades 31, 32, 3
Although the structure constituted by 10, 320 is shown, the invention is not limited to this, and the stopper of the present invention can be applied to a structure composed of one shutter blade. Further, in the above embodiment, the closing stopper 1
The inclined surfaces 13a, 14 only on 3, 14, 130, 140
Although the structure in which a, 130a, and 140a are provided is shown, the invention is not limited to this, and a similar inclined surface is also provided to the opening stopper to prevent the bounce phenomenon when the shutter blades 30 and 300 perform the opening operation. You may make it suppress or prevent.

[0036]

As described above, according to the shutter device for a camera of the present invention, a straight line passing through the support shaft of the shutter blade is provided as a stopper for abutting and stopping the shutter blade operated by the electromagnetic drive source. By providing the inclined surface inclined with respect to, the reaction force due to the impact force when the shutter blade travels (rotates) and comes into contact with the stopper is reduced, so that the bound phenomenon of the shutter blade can be suppressed or prevented. In particular, by providing an inclined surface with respect to the closing stopper, by suppressing or preventing the bounce phenomenon when applied as a shutter device of a digital camera in which the exposure time is defined by the closing operation of the shutter blades, A good exposure operation can be obtained. further,
Immediately before running the shutter blades, by energizing the electromagnetic drive source in the opposite direction, it is possible to eliminate the delay in the rise of the capacitor used in a normal feedback type constant current drive circuit, and to move the shutter blades with higher accuracy. Can be done.

[Brief description of drawings]

FIG. 1 is an external plan view showing an embodiment of a camera shutter device according to the present invention.

FIG. 2 is a developed sectional view of the camera shutter device shown in FIG.

FIG. 3 is a plan view showing a state in which a shutter blade is in a standby position with an opening portion opened.

FIG. 4 is a plan view showing a state in which the shutter blades are running in a closed state to close an opening and are in a closed position.

FIG. 5 is an operation explanatory view for explaining a force relationship between a shutter blade and a closing stopper.

FIG. 6 is a time chart for explaining energization control and exposure operation in the camera shutter device according to the present invention.

FIG. 7 shows another embodiment of the camera shutter device according to the present invention, and is a plan view showing a state in which the shutter blade is in a standby position with an opening portion opened.

FIG. 8 is a plan view showing a state in which the shutter blades of the apparatus shown in FIG. 7 are in a closed position where the shutter blades are closed and run to close the openings.

9 is an operation explanatory view for explaining a force relationship between a shutter blade and a closing stopper in the device shown in FIG.

FIG. 10 is an operation explanatory view for explaining the force relationship between the shutter blade and the stopper in the conventional camera shutter device.

[Explanation of symbols]

10 Main plate (substrate) 10a opening 11,12 spindle 13, 14 Close stopper 13a, 14a inclined surface 15, 16 opening stopper 30 shutter blades 31 First shutter blade 31c Tip edge 32 Second shutter blade 32c tip edge 40 Electromagnetic actuator (electromagnetic drive source) 41 rotor 41a Drive pin 130, 140 Close stopper 130a, 140a inclined surface 300 shutter blades 310 First shutter blade 310c Root side edge 320 Second shutter blade 320c Root side edge A straight line passing through the L spindle

Claims (4)

[Claims] 1. A substrate having an opening for exposure, a shutter blade rotatably supported around a support shaft on the substrate to open and close the opening, and an electromagnetic drive source for driving the shutter blade. A shutter for abutting and stopping the shutter blade operated by the electromagnetic drive source, wherein the stopper contacts the shutter blade,
Having an inclined surface inclined with respect to a straight line passing through the spindle,
A shutter device for a camera characterized by the above. 2. The shutter device for a camera according to claim 1, wherein the stopper is a closing stopper that stops the shutter blade after the closing operation of the opening. 3. The shutter device for a camera according to claim 1, wherein the inclined surface is formed so as to face an outer side that does not face the support shaft. 4. A control unit for controlling energization to the electromagnetic drive source, wherein the control unit sets a direction in which the shutter blade travels with respect to the electromagnetic drive source immediately before the shutter blade travels. 4. The shutter device for a camera according to claim 1, wherein the electric power is supplied in the opposite direction.